Long lip crucible



Aug. 9, 1960 G. R. PETERS LONG LIP CRUCIBLE Filed June 10, 1955 UnitedStates Patent 2,948,522 7 time LrP CRUCIBLE George R. Peters,Philadelphia, Pa., assignor to Ross- Tacony Crucible Co., Philadelphia,Pa., a corporation of Pennsylvania Filed June 10, 1955, Ser. No. 514,544

Claims. (Cl. 263-48) struct the long lip crucible of this invention of arefrac- 2 tory composition utilizing residual carbon bonding. Ex-

perience has shown that such refractory compositions are superior toother compositions in the manufacture and use of crucibles. Examples ofcarbon bonding compositions are those given in U.S. Patent No.2,013,625, issued September 3, 1935, to K. E. Buck. Carbon bonding,'which results from carbonization of ingredients such as tar and pitch,is highly resistant to weakening at high temperatures and to thermalshock. Consequently, crucibles made of compositions utilizing a residualcarbon bonding stand up very well in use and have long life.

In the construction of any long lip crucible, it is necessary to formthe long pouring lip separately from the body or pot of the crucible andthen attach the lip to the body in the finished crucible. For manyyears, cement was employed as the sole means of attachment of the longlip to the body or pot. This practice had serious disadvantages but itwas followed of necessity for lack of a. better method. Some of thedisadvantages of this practice are the following.

occasioned by fastening the same to a furnacelining.

attachment of the lip at the place of manufacture introduces problemswithrespect to shipping of the long [lip crucible as a whole and theconsequent increase of risk of breakage in transit. 2

In my copending application Serial No. 344,570, filed March 25, 1953,now abandoned, there is disclosed and claimed a'method of constructingcarbon bonded long lip crucibles by which the lip is eifectivelyintegrated with the body or pot. 'I hat method eliminates the cementedjoint \andove'rcomes the objections thereofwith respect to weakness ofthe joint but, since it involves integration of the long lip with thepot at the time of manufacture, it necessitates shipment of the crucibleas a whole 'totheuser, which makes shipment diflicult and increases theyrisk of breakage in transit.

, The principal object of the present invention is to provide a long lipcrucible construction which obviates all of the abovermentionedobjections.

, .By this invention, there is provided a construction which iscomparable in strength to the integrated struc- In some instances, theadhesi0n between the pot and the lip is not adequate to withstandstrains imposed onit by the weight of the metal onthe lip during pouringand also strains on the lip ice ture produced by the method of myabove-mentioned 'copendin-g application, but which is less expensive andenables shipment of the crucible with the long lip Idetached from thebody or pot, the lip being easily attachable by the user.

In accordance with this invention, a long lip crucible is provided whichcomprises a crucible body or pot, a long pouring lip, and inter fittingportions on said body and said lip, one of said portions having anopen-faced recess with an inwardly declined bottom surface and inwardlydivergent side surfaces, and the other of said portions being slidablyinsertable from the top into said recess and having surfacescomplemental to said recess surfaces. Preferably, the side surfaces ofsaid recess are divergent both inwardly and upwardly, and thecomplemental side surfaces of the insertable portion are formedaccordingly. Preferably also, the joint surfaces are coated ashereinafter described.

The invention may be fully understood by reference to the accompanyingdrawing, wherein Fig. 1 is a perspective view of a long lip crucibleconstructed according to the present invention; I

Fig. 2 is a plan view of the --interfitting portions of the pot and thelong lip;

Fig. 3 is a perspective View of the lip attachment portion of thecrucible body or pot, without the lip attached thereto;

Fig. 4 is a perspective view. of the detached long lip showing theattachment portion thereof; and

Fig. 5 is a sectional view taken along line 55 of Fig. 1.

In the construction of a long lip crucible according to this invention,the body or pot may be formed by molding of the material in soft plasticstate and by building up the lip-attachment portion of the pot by meansof suitable forming and tamping tools. The long lip may be formed in asimple press or mold having the desired shape of the lip, the materialbeing placed therein in soft plastic state. Following the formation ofthe pot and the long lip with the material in plastic state, each issubjected to the usual treatment to efiect curing and finishing. Wherethe pot and the long lip are formed of a refractory mixture utilizingresidual carbon bonding,

attachment portion 11, and a long lip 12 having an attachment endportion 13. As may be clearly seen in Figs. 3 and 5, portion 11 of thepot is a thickened wall portion at the upper part of the pot, and thisportion has an outwardly facing recess 14, preferably of substantialwidth and depth, extending downward from the. top

thereof. By substantial is meant large enough to acoommodate the meetingend of the lip, said lip having a trough of a size adequate to handlevthe charge of the crucible and having side walls at least as thick asthe walls of the crucible at points where the crucible wall is notthickened. The recess has an inwardly declined bottom surface 15, and ithas side surfaces 16 and '17 which are divergent bot-h inwardly andupwardly, Behind the recess is a residual wall portion 14a continuouswith the inner Wall of pot 10 but thinner by the depth of the recess 14than thickened wall portion 11. At the top of the pot and behind recess-14, a recess 18 in residual wall portion 14a is provided whichconstitutes an exit for molten material during pouring.

The long lip 12 is generally of trough form to. convey molten materialleaving the pot by way of exit --18.

The attachment portion *13of the lip is-of'wi'dth and depth to fittightly in recess 14, and has a bottom surface 19 declined toward theentrance end of the lip, and also has side surfaces'20 and 21 which aredivergent both upwardly 'and towardsaid end. These surfaces arecomplementalrespectively-to the surfaces 15 to 17 'of 'recess14.

Prior to attachment of the lip to the pot, a refractory coating ispreferably applied to the interfitting surfaces. A suitable coatingisa-mixture of 75% calcined powdered Kyanite and 25% fire clay. Thiscoating acts as a drying agent and also retardsexuding of the glaze fromthe end portion 13 of the lip downwardly into the recess 14 from the topthereof. The interlocking structure possesses great strength, and makesthe crucible as a whole as strong as if the lip actually were integratedwith the pot. In fact, tests have shown that the interlocking structureis actually the strongest part of the crucible.

In addition to great strength of the juncture between the long lip andthe pot, the construction provided by this invention enables shipment ofthe crucible with the long lip detached from the pot. As previouslyindicated, this simplifies shipping and lessens the risk of breakage intransit. The long lip is so easily attachable -to the pot that'anyonecan perform the attaching operation. Thus, the lip is easily attachableto the pot at the place of use.

A further advantage of this construction is that the pot may be insertedin a cold furnace without the lip attached thereto, and then the lip maybe attached to the pot.

A further important advantage of this construction is that it affords atight joint between the pot and the long lip, so that no leakage cantake place at the joint.

By way of'specific example of the preferred form of this invention, inone physical embodiment the pot has an outside diameter of 27", a heightof 35", and a wall thickness of 1%". The thickened wall portion has athickness of approximately 4" and the outwardly facing recess isapproximately 1 /2" deep. The lip has a length of 14%". The interfittingrecess and entrance end of the lip are approximately 6" high, 7" wide atthe bottom, and 9" wide at the top.

While a preferred embodiment of the invention has been illustrated anddescribed, the invention is not limited thereto but contemplates suchmodifications and other embodiments as may occur to those skilled in theart.

I claim:

1. A long lip crucible, comprising a crucible body or pot of refractorymaterial having a thickened wall portion at the upper part thereof, saidportion having an outwardly facing recess leaving a residual wallportion, said recess extending downward from the top thereof andinwardly to said residual wall portion, said recess having anessentially planar, inwardly declined bottom surface and havingessentially planar, inwardly divergent side surfaces, said pl anarsurfaces meeting in corners at angles of at least 90, and a long pouringlip of refractory material having an entrance end portion dimensioned tofit tightly in said recess with the end of the lip tightly against theresidual wall portion, said end port-ion having an essentially planarbottom surface declined toward said end and having essentially planarside surfaces which are divergent toward said end, said surfaces of thelip being complemental to said surfaces of said recess for interlockingnon-twistable engagement of said end portion'of the lip with said wallportion by insertion of said end portion. downwardly into saidrecessfr'om the top thereof. 7 V a '2. A long lip crucible, comprising acrucible body or i pot of refractory material having a thickened wallportion at the upper part thereof, said portion having an outwardlyfacing recess leaving a residual wall portion, said recess extendingdownward from the top thereof and inwardly to said residual wallportion, said recess having an essentially planar, inwardlydeclinedbottom surface and having essentially planar, side surfaces which aredivergent both inwardly and upwardly, said planar surfaces .meetingin-corners at angles of at'least and a long pouring lip of refractorymaterial having an entrance end portion dh'nensioned to fit tightly insaid'recess with the end of the lip tightly against the residual wallportion, said end portion having an essentially planar bottom surfacedeclinedtoward said endandhaving essentially planar side surfaces whichare divergent both upwardly and toward said end, said surfaces of thelip being complemental to said surfaces of said recess for interlocking,non-twistable engagement of said end portion of the lip with said wallportion by insertion of said end portion downwardly into said recessfrom the top thereof.

3. A long lip crucible, comprising a crucible body or pot of refractorymaterial having a thickened wall portion at the upper part thereof, saidportion having an outwardly facing recess of substantial width and depthleaving a residual wall portion, said recess extending downward from thetop thereof and inwardly to said residual wall portion, said recesshaving an essentially planar inwardly declined bottom surface and havingessentially planar, inwardly divergent side surfaces, said planarsurfaces meeting in corners at angles of at least 90, and a long pouringlip of refractory material having an entrance end portion dimensioned tofit tightly in said recess with the end of the lip tightly against theresidual wall portion, said end portion having an essentially planarbottom surface declined toward said end and having essentially planarside surfaces which are divergent toward said end, said surfaces of thelip being complemental to said surfaces of said recess for interlocking,non-twistable engagement of said end portion of the lip with said wallportion by insertion of said end portion downwardly int-osaid recessfrom the top thereof.

4. A long lip crucible, comprising a crucible body or pot of refractorymaterial having a thickened wall portion at the upper part thereof, saidportion having an outwardly facing recess of substantial width and depthleaving a residual wall portion, said recess extending downward from thetop thereof and inwardly to said residual wall portion, said recesshaving an essentially planar, inwardly declined bottom surface andhaving essentially planar side surfaces which are divergent bothinwardly and upwardly, said planar surfaces meeting in corners at anglesof at least 90, and a long pouring lip of refractory material having anentrance end portion dimensioned to fit tightly in said recess with'theend of the lip tightly against the residual wallportion, said endportion having an essentially planar bottom surface declined toward saidend and having essentially planar side surfaces which are divergent bothupwardly and toward said end,'said surfaces of the lip beingcomplemental to saidsurfaces of said recess for interlocking, 'nontwistable engagement of said end portion of the lip with saidwallportion by insertion of said end portion'downwardly into said recessfrom the top thereof.

5. A long lip crucible, comprising a crucible body or pot of refractorymaterial having a thickened wall portion at the upper part thereof, saidportion having an outwardly facing recess leaving a residual wallportion, said recess extending downward from the top thereof andinwardly to said residual wall portion, said recess providing anessentially planar bottom ledge and havin said recess with the end ofthe lip tight against the References Cited in the file of this patentWall, said end portion having an essentially planar bottom surfaceadapted to rest on the bottom ledge of the re- 2 UNITED STATES PATENTScess and having essentially planar side surfaces which are 191,000Campbell May 22, 1877 divergent toward said end, said surfaces of thelip being 5 540,292 Altmeyer June 4, 1895 complemental to said surfacesof said recess for inter- 1,673,115 Hauman June 12, 1928 lockingnon-twistable engagement of said end portion 2,195,523 South Apr. 2,1940 of the lip With said wall portions by insertion of said 2,670,108Skogstad et al.' 'Feb. 23, 1954 end portion downwardly into said recessfrom the top 2,793,021 Courtney May 21, 1957 thereof. 10 2,801,839Lemmer Aug. 6, 1957

